Extract swt.jar from the x86_64 file and rename it as swt-64.jar, and extract swt.jar from the second file. I saved them both to the home directory. (You can do this from terminal from the directory in which you saved the .zip files):

Then you need to copy these to the CrashPlan library. On my HDA CrashPlan was installed to /var/hda/web-apps/crashplan/html. If your installation is different you will need to replace the commands below this your directory.

Stop the crashplan server

Back up the old files and copy in the new ones (change the directory path to your own if it is different and remember to put the /lib at the end):

Should be working now.